Several vulnerabilities have been discovered in the Linux kernel that may leadto a privilege escalation, denial of service or information leak. The CommonVulnerabilities and Exposures project identifies the following problems:

CVE-2009-4067

Rafael Dominguez Vega of MWR InfoSecurity reported an issue in the auerswald module, a driver for Auerswald PBX/System Telephone USB devices. Attackers with physical access to a system's USB ports could obtain elevated privileges using a specially crafted USB device.

Kees Cook discovered an issue in the /proc filesystem that allows local users to gain access to sensitive process information after execution of a setuid binary.

CVE-2011-2209

Dan Rosenberg discovered an issue in the osf_sysinfo() system call on the alpha architecture. Local users could obtain access to sensitive kernel memory.

CVE-2011-2211

Dan Rosenberg discovered an issue in the osf_wait4() system call on the alpha architecture permitting local users to gain elevated privileges.

CVE-2011-2213

Dan Rosenberg discovered an issue in the INET socket monitoring interface. Local users could cause a denial of service by injecting code and causing the kernel to execute an infinite loop.

CVE-2011-2484

Vasiliy Kulikov of Openwall discovered that the number of exit handlers that a process can register is not capped, resulting in local denial of service through resource exhaustion (cpu time and memory).

CVE-2011-2491

Vasily Averin discovered an issue with the NFS locking implementation. A malicious NFS server can cause a client to hang indefinitely in an unlock call.

CVE-2011-2492

Marek Kroemeke and Filip Palian discovered that uninitialized struct elements in the Bluetooth subsystem could lead to a leak of sensitive kernel memory through leaked stack memory.

CVE-2011-2495

Vasiliy Kulikov of Openwall discovered that the io file of a process' proc directory was world-readable, resulting in local information disclosure of information such as password lengths.

CVE-2011-2496

Robert Swiecki discovered that mremap() could be abused for local denial of service by triggering a BUG_ON assert.

CVE-2011-2497

Dan Rosenberg discovered an integer underflow in the Bluetooth subsystem, which could lead to denial of service or privilege escalation.

CVE-2011-2525

Ben Pfaff reported an issue in the network scheduling code. A local user could cause a denial of service (NULL pointer dereference) by sending a specially crafted netlink message.

CVE-2011-2928

Timo Warns discovered that insufficient validation of Be filesystem images could lead to local denial of service if a malformed filesystem image is mounted.

CVE-2011-3188

Dan Kaminsky reported a weakness of the sequence number generation in the TCP protocol implementation. This can be used by remote attackers to inject packets into an active session.

CVE-2011-3191

Darren Lavender reported an issue in the Common Internet File System (CIFS). A malicious file server could cause memory corruption leading to a denial of service.

This update also includes a fix for a regression introduced with the previoussecurity fix for CVE-2011-1768 (Debian: #633738)

For the oldstable distribution (lenny), this problem has been fixed in version2.6.26-26lenny4. Updates for arm and alpha are not yet available, but will bereleased as soon as possible. Updates for the hppa and ia64 architectures willbe included in the upcoming 5.0.9 point release.

The following matrix lists additional source packages that were rebuilt forcompatibility with or to take advantage of this update:

Debian 5.0 (lenny) user-mode-linux 2.6.26-1um-2+26lenny4

We recommend that you upgrade your linux-2.6 and user-mode-linux packages.These updates will not become active until after your system is rebooted.

Note: Debian carefully tracks all known security issues across everylinux kernel package in all releases under active security support.However, given the high frequency at which low-severity securityissues are discovered in the kernel and the resource requirements ofdoing an update, updates for lower priority issues will normally notbe released for all kernels at the same time. Rather, they will bereleased in a staggered or "leap-frog" fashion.

Further information about Debian Security Advisories, how to applythese updates to your system and frequently asked questions can befound at: http://www.debian.org/security/